Windproof plumb bob



Patented Mar. 27, 1934 WINDPROOF PLUMB BOB y Patrick Deasy, Chicago, Ill.

Application May 25, 1931, Serial No. 539,683

3 Claims.

This invention relates to an improved Windproof plumb bob, and has for one of its principal objects the provision of a plumb bob which can be used in the open Vand under all conditions of Aweather without interfering in any way with its eiciency or accuracy.

One of the important objects of this invention is the provision of a plumb bob which will be proof against high winds, and which furthermore shall have its swinging movements damped, so that an accurate reading thereof is promptly available, whereby considerable time in operation is saved.

Still another important object of the invention resides in the provision of a plumb bob which shall be so constructed that it will accurately center itself with relation to an inclosing housing when the bob and the housing are in a vertical position.

Other and further important objects of the invention will be apparent from the disclosures in the accompanying drawing and following Y ification.

Theinvention, in a preferred form, is illustrated in the drawing and hereinafter more fully described.

In the drawing:

Figure 1 is a side elevation of the improved wind-proof plumb bob of this'invention, showing the same as applied to a column or receptacle for reinforced concrete, or any portion of a building or structure. l

Figure 2 is a detail sectional view of the lower portion of the plumb bob.

Figure 3 is a detail view, partly in section, of the upper portion of the apparatus.

Figure 4 illustrates a joint for removably fastening portions of the housing together.

Figure 5 is a sectional view taken on the line 5-5 of Figure 2, looking in the direction indicated by the arrows.

As shown in the drawing:

The reference numeral 10 indicates generally any structure which it is desired to accurately position vertically. This may be a portion of a building or other structure, and in the drawing, represents particularly a column or receptacle such as those ordinarily used for filling with reinforced concrete in the construction of fireproof buildings or the like. The reference numeral 12 indicates a brace which is applied to the column, and which extends downwardly and laterally for fixing the same in desired vertical position after the same has been plumbed.

The wind-proof plumb bob itself of this invention consists of a casing or receptacle 14 which forms the bottom of the device and which is kept about three-fourths filled with oil, glycerine, or some other preferably viscous liquid as illustrated at 16. Adapted to be removably attached to the upper edge of the receptacle 14 is a sleeve 18, preferably of aluminum or some similar suitable material, the attachment being removable, and being made by means of pin 20 operating in bayonet slots or the like formed in the lower portion of the sleeve 18. Another sleeve 22 is likewise removably attached to the sleeve 18 by means of pins 24 operating in bayonet slots 26 as best shown in Figure 4, and a further and similar attachment is made with an additional sleeve 28 as illustrated in Figure l. Obviously, the complete length of the joined sleeves is variable to conform to the requirements Vof the device or structures being aligned at the moment, but it might be explained that the reinforced columns for which this device is particularly adapted are approximately ten feet high in the usual building, and therefore, the assembled length of the wind-proof plumb bob should be around nine feet.

' The uppermost sleeve 28 is closed with a cap or the like 30 which is removable to allow of ,ready access to the interior, and adjacent the upper edge is removablypositioned a spindle or the like 32 upon which is wound a length of supporting cord 34 asbest shown in Figure 3. The `spindle is rotatably mounted in suitable slots in the sides of the sleeve 23, the rotation being rendered possible by means of rounded projections or axles 36 as shown. A notch or the like 38 is cut into the spindle 32 which is also of metal or similar material, the length of the string or cord 34 being passed through the notch at a point so that the plumb bob 40 at its lower end will, when the string is unwound to this point, be suspended in 95 the liquid 16 in the bottom receptacle 14 as illustrated in Figure 2.

A pair of supporting brackets in the nature of braces are supplied for the device, one designated by the reference numeral 42 being at the top and the other being at the bottom as shown at 44. These braces are accurately made so as to conform exactly to each other, particularly in length, and each brace encircles its corresponding sleeve and is adapted to be fixed thereon by means of a set screw or the like 46. At the point where the cord 34 leaves the spindle 32, it passes through a small opening formed in the plate 50 fixed in the upper end of the sleeve 28 as best shown in Figure 3, this opening being accurately centered in no 'LIDO sections 18, 22, and 28 while in the exact centerk thereof.

Adjacent the lower end of the device and in the sleeve 18 is an opening 52 which is normally closed by means of a pane of glass or the like 54 in a frame 56. As best shown in Figure 5, the frame is mounted on hinges or the like 5S so that the same may-be opened if access is desired to the interior of the tube, and a latch 60 is .provided whereby the same may be fastened in closed position. On a quiet or still day when no great Wind is blowing the Window may be left open for slightly more convenient observation of the plumb bob and line. 56 is mounted on an inwardly projecting shelf or the like 62, this shelf having a mark 64 in the middle thereof whereby the cord or string 34 may be accurately aligned with respect to the center vof the tube 52. If desired, the interiorof the tube may be illuminated by a flashlight or the like for better observation, or the marker 64 can be outlined in some luminous paint which makes it particularly adaptable for work in dark places. The cord may, of course, be also so treated.

The device can be readily assembled and may be made telescoping for ready adjustment to various jobs. When the plumb bob is immersed 'in the liquid, its oscillations or swinging movements will Abe considerably damped so that a quick reading can be made. In the event that the column is not straight, it can be moved as indicated by the observer at the plumb bob, and the oscillations of the line will cease in a very short time,-thereby enabling a very prompt and accurate reading of the results of such movement.

It'will be seen that herein is provided a windproof plumb -bob which being inclosed will eliminate inaccuracies, and will also constitute quite an improvement over the old method of aligning vstructures or portions of structures, as on a windy The lower edge of the hinged frame and also for adaptation to various jobs. The nature of the supporting and bracing brackets is such that the apparatus can be readily positioned on most any kind of Work without interfering with projections on the work, and without making any allowance for such projections. Additionally, the wide bases on the brackets insure an accurate positioning of the apparatus against the surface of any object which is to be framed.

I am aware that many changes may be made and numerous details of construction varied throughout a wide range without departing from the principles of this invention, and therefore,

.do not purpose limiting the patent granted hereon otherwise than as necessitated by the prior art.

I claim as my invention:

1; A wind-proof plumb bob, including a sectional housing, and a plumb bob and line in the housing, one section containing means for damping the oscillations of the bob, together With'means for allowing observation of the position `of the line in the housing, said means comprising a window in that section of the housing adjacent the lower end thereof, and a center marking adjacent the window.

y 2. A wind-proof plumb bob, including a sectional housing, and a plumb bob in the housing, means for demping the oscillations of the bob and means adjustably suspending the plumb bob in the housing, said means comprising a spindle in the top of the housing, and a cord for the plumb bob adapted to be Wound on the spindle, centering means for the oord, and a windowiadjacent the lower end of the housing for allowing observation of the plumb-line.

3. A wind-proof plumb bob, including a housing, and a'plumb bob in the housing, means axed to the lower end of the housing for damping the oscillations ofrthe bob and means for adjustably suspendingthe plumb bob in the housing, said means comprising a spindle in the top` of the housing, and a cord for the plumb bob adapted to be wound on the spindle, a recessed window adjacent the lower end of the housing for allowing observation of the plumb-line, a centering marker on the housing inside the window and a notch in the spindle for adjustably iixing the operating length of the cord, while at the same time allowing winding thereof within the said operating length.

PATRICK DEASY. 

